Apparatus and method for local application of polymeric material to tissue

ABSTRACT

An apparatus is provided for applying to a surface of mammalian tissue including soft, living tissue an initially fluent material and then activating the material by exposure to an energy source. The material may be a liquid capable of polymerization to a non-fluent state by exposure to actinic light. The device, and methods that may be practiced in association with the device, enable a wide range of medical conditions to be treated including, for example, the application of a barrier to, soft tissue to prevent post-surgical adhesions.

This application is a continuation of application Ser. No.PCT/US94/03115, filed Mar. 23, 1994, which is a continuation-in-part ofU.S. Ser. No. 08/036,128, filed Mar. 23, 1993, now abandoned.

FIELD OF THE INVENTION

This invention relates to devices and techniques for applyingtherapeutic polymeric material to living tissue.

BACKGROUND OF THE INVENTION

A number of photopolymerizable hydrogel polymers that may be applied tomammalian tissue, including soft, living tissue, in order to treatvarious medical conditions are disclosed in the following U.S. patentapplications:

U.S. patent application Ser. No. 843,485 filed Feb. 28, 1992 (Hubbell etal.) and a continuation-in-part thereof, Ser. No. 08/022,687 filed Mar.1, 1993,

U.S. patent application Ser. No. 07/870,540 filed Feb. 28, 1992 (Hubbellet al.) and a continuation-in-part thereof, Ser. No. 08/024,657 filedMar. 1, 1993.

The hydrogels disclosed in the foregoing applications may be applied toliving tissue, for example, for the prevention of post-operativeadhesions, the protection of tissue surfaces, the local application ofbiologically active species, and the controlled release of biologicallyactive agents to achieve local and systemic effects. They also may beused as temporary or long-term tissue adhesives or as materials forfilling voids in biological materials. The materials and conditions ofapplication are selected to enhance desirable properties such as goodtissue adherence without adverse tissue reaction, non-toxicity, goodbiocompatability, biodegradability when desired, and ease of applicationor handling.

The composition that will form the polymerized hydrogel may include alight sensitive polymerization initiator and is applied to the tissuesurface in fluent form, as a liquid. The coated tissue then is exposedto light to polymerize the composition and render it non-fluent, insitu. The light is selected to be of an appropriate wavelengthto-efficiently initiate or sustain the polymerization and is of anappropriate intensity to achieve the polymerization within the desiredtime.

Reference is made to the above-identified patent applications for adetailed description of various hydrogels usable in this invention,their compositions, manufacture and general use. The disclosures of theabove-identified applications are incorporated by reference as part ofthe disclosure herein.

SUMMARY OF THE INVENTION

The invention includes devices for applying a polymeric material to asurface of targeted tissue within a patient. The coating is applied as apredetermined volume of prepolymer composition which, after application,is irradiated with light to initiate and cause polymerization orgellation. The device includes a reservoir for the prepolymer liquid andan outlet adapted to eject the liquid onto the tissue surface in apredetermined pattern. A pumping arrangement is provided to causetransfer of a predetermined volume of prepolymer liquid stored in areservoir to the outlet and for ejecting the liquid from the outlet. Theoutlet is arranged to cause the liquid to be emitted to form apredetermined pattern. The device also includes means for activating thefluent prepolymer liquid to render it non-fluent. The activating meansmay be a form of light that may be generated locally or conductedthrough an optical fiber from an external light source. The device hasan optical emission aperture at its distal end and is arranged inassociation with the prepolymer outlet to direct light emission in thesame direction. Operation of the various components of the system may becontrolled by a microprocessor.

In one specific embodiment of the invention, the device is gas-poweredand has an emission nozzle for the prepolymer liquid at its distal end.The nozzle arrangement is adapted to develop a low pressure emission ofgas (e.g., CO₂) and a lumen is provided in the device and to communicatethe gas to the nozzle from a source of pressurized gas. The outletnozzle is arranged so that, while gas is being emitted, a bolus ofprepolymer liquid injected into the gas stream will cause the liquid toform a desired pattern, as in a divergent spray. The device alsoincludes an optical fiber having an emission aperture at the end of thedevice, adjacent to the outlet nozzle. After the prepolymer liquid hasbeen applied to the tissue, the activating light is applied to renderthe liquid to a non-fluent state.

In another embodiment, the fluent prepolymer liquid is subjected to asudden controlled pulse of high pressure to force a predetermined volumeof the liquid through the delivery outlet. The arrangement includes avariable volume reservoir (e.g., a syringe) for the liquid that isoperated rapidly and under a force adequate to develop sufficientpressure to emit the liquid from the outlet and deposit it on the tissuein a desired pattern. In this embodiment, the reservoir is mounted in adevice that includes a driver element engageable with a movable part ofthe reservoir. The driver element is movable in predetermined incrementsto reduce the reservoir volume in sudden, controlled, forceful pulses tocause the ejection of the predetermined volume of liquid from theoutlet. The device may include a spray nozzle at the outlet, with thedriving system being sufficient to develop sufficient pressure, andpulse characteristics to cause the desired spray pattern. The devicealso may include an optical system to irradiate the applied liquid withlight to activate the material.

The driving element may be powered by a self-contained power source suchas a relatively high compression spring associated with a triggermechanism that enables the spring first to be cocked (compressed) andthen fired (released) to provide the driving force for the driverelement.

In another aspect of the invention means are provided to facilitatepositioning of the distal, emission end of the device with respect tothe target tissue.

It is among the general objects of the invention to provide devices andtechniques for efficiently and effectively applying a fluentpolymerizable material (referred to as a "prepolymer") to targetedtissue, including living tissue, and for effecting polymerization of thefluent prepolymer composition in situ to a non-fluent state.

Another object of the invention is to provide a device of the typedescribed in which the device applies a predetermined volume of thematerial for each operating cycle.

A further object of the invention is to apply the polymerizable materialin a thin film sprayed on the targeted tissue.

An additional object of the invention is to provide means fordetermining the position of the distal end of the device from the tissueto be coated, and to facilitate aiming the device to control thethickness and location of the coating.

Another object of the invention is to provide a device of the typedescribed that is suited particularly, although not exclusively, for usein endoscopic or laparoscopic surgery.

In another embodiment of the invention, means may be provided tofacilitate the physician in determining the orientation and spacing ofthe distal end of the applicator device from the targeted tissue. Suchmeans may take the form of a tissue engaging element attached to andextending distally a known distance from the distal end of theapplicator. The physician can observe, as by a laparoscope, the contactof the distal end of the tissue contacting device thereby providinginformation as to the spacing and orientation of the applicator. Inother aspects, the physician may obtain information as to the spacingand orientation of the device by directing light from the optical systemagainst the targeted tissue and by observation of the light on thetissue to judge the distance and orientation of the distal end of theapplicator with respect to that tissue.

In another aspect of the invention, means may be provided to aspirate,from the distal tip of the device, any excess drops of liquid that mightcollect on the tip.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects and advantages of the invention will beappreciated more fully from the following further description thereof,with reference to the accompanying drawings wherein:

FIG. 1 is an illustration of the system including the applicator, thecontrol module and the cable connecting the control module andapplicator;

FIG. 2 is a schematic illustration of the operating elements of theapplicator;

FIG. 3 is an end view of the distal end of the applicator shaft;

FIG. 4 is an illustration of the manner in which the syringe reservoiris loaded into the handle;

FIG. 5 is an illustration of the manner in which the device may be usedin a laparoscopic procedure;

FIG. 6 is a fragmented sectional illustration of another embodiment ofthe invention;

FIG. 7 is a top view of the housing of the embodiment of FIG. 6;

FIG. 8 is a fragmented, partly sectional illustration of the device asseen from above;

FIG. 9 is an illustration of the trigger mechanism in a cockedconfiguration;

FIG. 10 is an illustration of the trigger mechanism in a firedconfiguration;

FIG. 11 is a fragmented perspective of a portion of the drive mechanism;

FIG. 12 is another fragmented illustration of a portion of the drivemechanism illustrating additional details thereof;

FIG. 13 is an enlarged sectional illustration of the means for limitingthe extent of movement of the driving pawl;

FIG. 14 is an end view of the distal tip of the device shown in FIG. 6;

FIG. 15 is a sectional illustration of the distal tip of the device asseen along the line 15--15 of FIG. 14;

FIGS. 16A-16C illustrate sequentially the engagement of the driving pawlwith the driver as the driving pawl is first retracted, re-engaged witha different group of teeth on the driver and then advanced one incrementto advance the driver one increment in an ejection stroke;

FIGS. 17A-17B illustrate the manner in which the pawl release effectsdisengagement of the driving pawl from the driver;

FIG. 18 is an exploded view of the components of the device;

FIG. 19 is a sectional illustration taken along the line 19--19 of FIG.6; and

FIG. 20 is a plan view of the top of the device after the syringe hasbeen spent and in readiness for operation of the pawl release mechanismby which the driver is retracted to its rearward position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description of the invention is made in thecontext of use as an adjunct to laparoscopic surgery. It should beunderstood, however, that the invention may be used in other surgicalenvironments where it may be beneficial to apply and polymerize materialdirectly on tissue.

In the following description, the term "distal" or "forward" will referto a direction toward the emission end of the devices (e.g., to the leftin FIG. 6) and "rearward" or "proximal" will refer to the opposite end,that is, toward the physician.

FIG. 1 is an illustration of the principal components of one embodimentof a system incorporating the invention. The system includes anapplicator, indicated generally at 10; a control module, indicatedgenerally at 12; and a transmission cord 14 that connects the controlmodule 12 to the applicator 10. The control module 12 may include alight source, (not shown), such as those described in theabove-mentioned Hubbell applications, to provide light necessary toinitiate the polymerization reaction. The control module 12 also mayinclude or be connected to a source of compressed gas such as (CO₂) andincludes the valves and other devices adapted to facilitate control ofthe pumping system, described below. The control module 12 also mayinclude microprocessors and associated electronics and displays tocontrol and monitor operation and sequencing of the various elements ofthe system.

The applicator 10 includes a handle 16 and, in the illustrativeembodiment adapted for use in a laparoscopic environment, a rigid shaft18. The shaft 18 is attached to and extends distally from the handle 16.As will be described in further detail, the distal tip 20 of the shaft18 includes an emission nozzle from which the prepolymer liquid issprayed and an emission aperture of an optical path arranged toirradiate the sprayed tissue with light. The nozzle arrangement isadapted to develop a low pressure emission of gas and a lumen isprovided in the device to communicate the gas to the nozzle from apressurized source of the gas. The outlet is arranged so that while thegas is being emitted, a bolus of prepolymer liquid injected into the gasstream will be atomized to cause the liquid to form a desired pattern,such as a divergent spray.

The transmission cord 14, has a channel to communicate compressed gas tothe applicator 10, an optical fiber or fiber bundle to couple light fromthe light source in the control module to the applicator 10 andelectrical conductors to connect electrically the electronic controls inthe control module with a triggering switch 22 associated with theapplicator handle 16. The triggering switch 22 may be incorporated in anend cap 24 that is detachably connectable to the main portion of thehandle 16. The proximal end of the handle 16, at the interface 26 withthe end cap 24, includes connectors 28, 30 which, when the end cap 24 isattached are coupled with corresponding connectors in the end cap 24 tocomplete the optical and gas transmission paths from the end cap to thehandle 16.

It is preferred that the components embodied in the handle 16 and shaft18 be formed from low cost materials and components and that moreexpensive components be incorporated into the control module or thetransmission cable and end cap. Thus, the handle and shaft portion ofthe device, or only the shaft portion, may be adaptable to disposable,one-time use.

FIG. 2 illustrates, schematically, an embodiment of the device thatincludes a gas-driven fluid pump arrangement, as well as the gas andlight systems and their associated controls. The system includes a pump,indicated generally at 32, and a reservoir 34 that may be in the form ofa syringe. In the illustrative embodiment, the pump mechanism 32 andsyringe 34, as well as a pair of one-way valves 36, 38 and theirassociated conduits are contained with the handle 16. The pump 32 ispneumatically driven and includes a pump cylinder 40 and a drivecylinder 42. A piston 44 is slidably contained in the pump cylinder 40and is connected by means, suggested schematically by rod 46, to apiston 48 slidably contained in the drive cylinder 42. The pistons 44,48 are movable together in a pumping stroke (to the right in FIG. 2) ortoward a retracted position in a filling stroke (to the left in FIG. 2).The pistons 44, 48 are biased toward a retracted configuration, as by aspring 50 illustrated. schematically as connected to the pistons 44, 48through a bracket 52 secured to or part of the rod 46. Preferably, thedevice has a fixed stroke adapted to pump an identical volume ofprepolymer liquid for each cycle. However, if desired, the length of thestroke of the pistons 44, 48 may be varied, as by providing anadjustable stop to vary the position to which the pistons are retracted.It is preferred that the pumping stroke extend from the retractedposition to a position in which the piston 44 engages the end 55 of thepump cylinder 40. When the pump is retracted in a filling stroke,prepolymer liquid from the syringe 34 is drawn through a conduit 56 andthe one-way valve 36 into the pump cylinder 40. When the pump is thendriven in a pumping stroke, the liquid is ejected through line 58 andone-way valve 38 to and out of the central orifice 60 at the nozzle 62.The volume of ejected liquid is the same for each cycle of the pump.

The system also includes a pneumatic conduit 64 that extends through thehandle 16 and shaft 18 and terminates at the nozzle 62. The nozzle 62may be configured to include an annular outlet orifice 66 that surroundsthe central orifice 60. Gas is communicated under pressure to thepneumatic conduit 64 through a normally closed solenoid valve 68. Thesolenoid valve 68 may be opened and closed under the control of amicroprocessor 70. The valve 68 is in communication through line 72 witha source of compressed gas such as CO₂. The source of compressed gas canbe any source with sufficient pressure such as a conventional tank andregulator, as in FIG. 1, or a small disposable gas cartridge mounted onthe handle, or a reservoir on the handle or elsewhere, pressurized bymechanical means.

The applicator also includes an optical fiber 74 or a bundle of suchfibers to transmit light from a light source 76 to a light emissionaperture 78 at the distal tip of the shaft 18. The light source 76 iscontrolled by a switch 77 that, in turn, is controlled by themicroprocessor. The light is switched on after the pumping stroke hasbeen completed and is allowed to remain on for a predetermined length oftime sufficient to assure full polymerization of the sprayedcomposition. The microprocessor and system controls may be configured toenable additional exposures of light independent of operation of thepump in the event that additional exposure is needed for fullpolymerization.

FIG. 3 illustrates the distal end face of the shaft 18 including thenozzle 62 and the distal emission face 78 of the optical fiber. Thenozzle 62 and the distal emission face 78 may be arranged side-by-sideand are oriented to emit a spray and light, respectively, alongsubstantially parallel axes.

The nozzle, in the illustrative embodiment, is selected so that it willdevelop a divergent, generally conical spray that, preferably, willcover a spot of about 3 cm in diameter when the nozzle 62 is spacedabout 2 cm from the surface of the target tissue. The optical fiber(s)is selected to have a numerical aperture such that the beam of lightthat is emitted from the emission aperture at the end of the fiber willdiverge sufficiently to define an irradiated spot about 4 cm in diameterat a distance of about 2 cm from the distal tip 20 of the shaft 18. Ifdesired, the emission aperture may be defined by a means other than theend of the fiber (e.g., a lens) to shape the beam of emitted energy orby a protective window. The preferred embodiment includes aconfiguration in which the spot defined by the irradiating light isgreater than and includes the spot covered by the spray pattern when thenozzle 62 and light emission aperture 78 are spaced the same distancefrom the target tissue. This assures that when the applicator ismaintained in the same position, the full area of tissue that has beensprayed will be irradiated sufficiently to effect adequatepolymerization. It should be understood that other beam or spraypatterns (e.g., rectangular, line, etc.) may be employed for use inspecial applications. It is preferred, however, that the pattern definedby the light be essentially the same as that of the spray in order tofacilitate aiming of the device.

FIG. 4 illustrates a manner in which the syringe 34 may be received inthe handle. The handle includes a socket 90 that is exposed when the endcap 24 is removed. The socket is receptive to the syringe and has, atthe bottom of the socket, a fitting adapted to couple, in a sealedmanner, to the distal tip 92 of the syringe. After the syringe has beenloaded with prepolymer liquid, it is inserted into the socket to effectthe coupling. The plunger 94 of the syringe then is advanced to ejectprepolymer liquid into the conduits 56, 58 and through the check valves36, 38, until the liquid drips out of the nozzle. The system then isprimed. The plunger of the syringe may be provided with a weakened line96 so that the proximate end of the plunger can be broken away after thedevice has been primed. With the proximal end of the plunger so trimmed,the end cap 24 then can be replaced on the handle 16 and the device isin readiness for use.

The prepolymer may be supplied in lyophilized form so that it may bemixed with suitable liquid (e.g., saline) immediately before beingloaded into the syringe.

FIG. 5 illustrates the manner in which the applicator may be used in alaparoscopic procedure to apply a thin film (e.g., of the order of 200microns thick per spray cycle) to a portion of the soft tissuecomprising a patient's uterus. After the completion of the laparoscopicsurgical operation here illustrated in connection with the uterus, andafter removal of the surgical instrument from the trocar cannula, theapplicator having been primed and set up in readiness for use, the shaftis passed through the trocar cannula 81. In the illustrative embodiment,the distal end 20 of the shaft 18 is positioned approximately 2 cm fromthe surface 83 of the uterus to be treated. The physician may observethe placement and orientation of the distal end 20 of the shaft throughthe laparoscope (not shown) that also is inserted into the patientthrough another trocar cannula (not shown). The device may be providedwith supplemental means to facilitate aiming and positioning of thedistal end of the shaft. For example, the device may include a controlto operate the irradiating light source independently of the operationof the pump in order to preview the region at which the device is aimed.It will be appreciated by those skilled in the art that such aimingfunction including the timing and operation of the light independentlyof the other components of the system may be incorporated into themicroprocessor or may be provided by a supplemental light source and/orcontrol.

The device also may incorporate means to facilitate positioning of thenozzle a precise distance from the tissue to be coated. For example, aproximity and position detector indicator may tare the form of one ormore slender, flexible feelers that project distally from the distal endof the device. When the distal tip(s) of the indicator engage(s) thetissue, that verifies the precise distance of the nip of the nozzle fromthat tissue. The physician can confirm, by observation through thelaparoscope, that the feeler has contacted the tissue. In another mode,the physician may be assisted in determining the spacing and orientationof the distal end of the nozzle with respect to the target tissue bypreliminarily irradiating the target tissue with light and observing theconfiguration of the light pattern on the tissue.

When the device is properly positioned and aimed, the physician actuatesthe system by triggering the switch 22. In this embodiment themicroprocessor controls operation of valve 68 that serves to admit orshut off air to the system. The microprocessor is arranged to open thevalve 68 to admit CO₂ from its source through conduit 72 andsimultaneously to branch conduits 64 and 80. Line 64 directs gas to theannular outlet 66 on nozzle 62. The compressed CO₂ passes through a flowrestrictor 82 and into the drive cylinder 42 to begin the pumpingstroke. It will be appreciated that at the beginning of the pumpingstroke the piston 44 will be fully retracted under the influence of thespring 50. The flow restrictor 82 serves to delay slightly the operationof the pump 32 sufficiently to enable the flow CO₂ out of the nozzle 62to be fully established. Thereafter, as the prepolymer liquid is pumpedout of the nozzle 62, it will merge with the gaseous stream to be formedinto a divergent spray and directed against the tissue as suggested inphantom at 86 in FIG. 4. The spray will continue until the piston 44 hasreached the end of its travel and abutment with stop 55. The gaseousstream emitted from the nozzle 62 is continued for a short time afterthe ejection of liquid has been completed. That assures that all of theemitted liquid will be converted into a spray and will be sprayedagainst the tissue surface. After the predetermined interval, which maybe programmed into the microprocessor, the valve 68 is caused to shutoff. The pump then is urged to its retracted configuration by the spring50 to reload the pump cylinder 40 with a fresh charge of prepolymerliquid. After the prepolymer has been applied to the tissue surface, thelight is transmitted through the optical fiber to polymerize theprepolymer.

It will be appreciated that where The area of tissue to be treated isgreater than the area that can be covered and irradiated in a singlecycle, the physician may apply a group of adjacent and overlapping spotsto the tissue in order to cover fully the area to be treated.

FIGS. 6-17 illustrate another embodiment of the invention in which themode of power for propelling the prepolymer solution includes acompression spring that is compressed and then released abruptly, theenergy of the release being applied to a drive mechanism that advancesforwardly the plunger of a syringe containing the prepolymer liquid.Means are provided for limiting the extent of travel of the plunger sothat the sudden force applied by the release of the spring will cause apredetermined quantity of prepolymer liquid to be ejected through anozzle, as in a spray, thereby coating the targeted tissue.

The applicator in this embodiment includes a housing 100 and a dependinghandle 102. The housing 100 may be formed from a pair of mirrorimage-half-sections secured together by fasteners 104 or other means.The device includes a tubular shaft 106 that may be rigid and formedfrom an appropriate biologically compatible material such as stainlesssteel. The shaft is adapted to be inserted into the patient, forexample, as through a trocar cannula 81 as illustrated in FIG. 5. Theshaft 106 may extend substantially fully through the length of thehousing 100 and distally from the distal end of the housing. The shaft106 includes a number of passageways, either in the form of separateinternal tubes or defined by the lumen of the shaft, for communicatingto the distal tip 108, liquid prepolymer and light for activation of theapplied liquid prepolymer. The shaft also may include a passagewaythrough which the region adjacent the liquid emission outlet can beaspirated to prevent liquid from dripping from the end of the tip 108.

The housing 100, when assembled, can be considered as including a topwall 110. The top wall is provided with brackets 112 arranged tosecurely, but detachably, hold a syringe 114. The syringe serves as avariable volume reservoir for the fluent prepolymer liquid. The outletof the syringe is connected, as by a luer fitting, to a flexible conduit116 that passes through an aperture 118 in the top wall 110. As shown inFIG. 6, the conduit 116 is connected to a liquid feed tube 120 withinthe housing. The feed tube 120 extends through the wall of the shaft 106and through the shaft lumen to a nozzle arrangement at the distal tip ofthe shaft. The feed tube 120 may be formed from an appropriate materialsuch as stainless steel tubing. The syringe 114 includes a plunger 122that is operated in short, abrupt increments. The plunger is driven in adistal direction by a driver lug 124 that is movably mounted in thehousing and projects upwardly through an opening 126 (FIG. 7) in the topwall 110, As described below in further detail, a driving mechanismcontained in the housing 100, controlled by operation of a trigger 128,is operable to advance the driver lug 124 in short, abrupt and forcefulincrements.

The drive mechanism is illustrated in FIGS. 8-13. The mechanism includesa linear ratchet best illustrated in FIG. 11. The linear ratchetincludes an elongated driver 130 having an inverted U-shaped transversecross section and having downwardly depending sidewalls 132 and aconnecting top wall 134. The lower edges of the driver sidewalls 132 aresupported by and are slidable in a forward and rearward direction alonga bottom wall 137 (FIG. 6) formed as part of the housing. The driver lug124 is secured to and extends upwardly from the proximal end of the topwall 134 of the driver. The inwardly facing surfaces of the driversidewalls 132 are provided with a plurality of teeth 136.

The driver 130 is driven forwardly by a linearly reciprocable drivingpawl 138. The driving pawl 138 is disposed within the driver 130 and isslidable in a forward and rearward direction The driving pawl 138 isgenerally U-shaped, having a pair of forwardly extending arms 140connected by a rear wall 142. The arms 140 are constructed to beflexible transversely and can bend inwardly toward each other. It may bedesirable to provide a slot 144 adjacent the juncture of each arm 140with the sidewall 142 to facilitate inward lateral bending of the arms140.

Each of the arms 140 is-spaced slightly from the inwardly facing teeth136 on the driver sidewalls, for purposes described below. The distalend of each of the arms 140 is provided with several teeth 146configured to engage the teeth 136 on the driver sidewalls 132. As willbe described in further detail below, the teeth 136, 146 are arranged sothat they lock together when the driving pawl 138 is advanced forwardlybut can disengage, in ratchet-like fashion, when the driving pawl 138 isdrawn rearwardly relative to the driver 130. Thus, it will beappreciated that as the driving pawl 138 is reciprocated forwardly andrearwardly within the housing (in a manner described below) the driver130 will be driven forwardly in increments as the pawl 138 movesforwardly but can be held stationary (by means described below) whilethe driving pawl 138 moves rearwardly relative to the driver 130.

The faces of the teeth 136, 146 that permit such linear ratchetingmotion are shown in FIG. 16A. The teeth 136, 146 define a sawtoothconfiguration. The teeth 136 each have a rearwardly facing transverseface 136R and a forwardly facing inclined face 136F. The teeth 146 onthe pawl 138 each include a forwardly facing transverse face 146F and arearwardly facing inclined face 146R. The engagement of the faces 146F,136R lock the driving pawl 138 to the driver 130 during forward movementof the driving pawl 138 while permitting the inclined faces 136F, 146Rto slide with respect to each other as the pawl arms 140 flexresiliently inwardly until the teeth of the driving pawl engage the nextrearwardmost teeth on the driver.

The driver 130 is maintained in its last advanced position duringretraction of the driving pawl 138 by a locking pawl 148. Asillustrated, the locking pawl 148 may comprise a thin U-shaped elementhaving a pair of forwardly extending legs 150 joined at their rearwardends. The rearward end of the locking pawl 148 is secured to the housing110 by any convenient means, such as a T-shaped element 150 received ina receptive bracket formed as part of the housing. The locking pawl 148is disposed between the driving pawl 138 and the bottom wall 137 of thehousing. The legs 150 of the locking pawl are flexible inwardly,similarly to the arms 140 of the driving pawl 138. The outwardly facingedge at the distal end of each of the arms 150 is provided with severalteeth 154, identical in contour to the teeth 146 on the locking pawl138. When the locking pawl 138 is driven forwardly to advance the driver130, the engagement of the locking teeth 154 with the driver teeth 136causes the arms 150 to flex inwardly to permit advancement of thelocking pawl 138 and driver 130. When the locking pawl 138 is retracted,however, the engagement of the locking teeth 154 with the driver teeth156 prevents rearward motion of the driver. This assures that when thelocking pawl 138 is retracted, the driving lug 124 on the driver 130will maintain a firm contact in the position against the proximal end ofthe syringe plunger, in readiness for the next ejection cycle.

FIGS. 6 and 9-12 illustrate, in further detail, the trigger and springmechanism by which the device is actuated. The trigger 128 is pivotallymounted to the housing at pivot 156. The upper region of the trigger isengageable with the distal end of a compression link 158. The proximalend of the compression link is pivotally mounted to the driving pawl138. between the arms 140, at pivot 160. The compression link isprovided with a passageway 159 that receives a portion of the shaft 106.The passageway 159 is sufficiently wide so as not to interfere with theshaft during the full range of movement of the compression link 158.

The driving pawl 138 is limited in its range of forward and rearwardmovement and is biased continually toward the forward extremity of thatrange. The range of movement is limited by an arrangement that includesa tubular spring housing 162 attached to and extending rearwardly fromthe rear wall 142 of the driving pawl 138. The spring housing 162 may beattached to the wall 142 by a threaded connection 164. The rear end ofthe spring housing 162 is closed by an end wall 166. The end wall 166 isprovided with an aperture 168 (See FIG. 13) that receives, slidably, acylindrical rear mount 170. The forward portion of the rear mount 170has a radially flared collar 172 that prevents separation of the springhousing 162 from the rear mount 170. Additionally, engagement of theflared collar 172 with the inner surface of the end wall 166 defines theforward limit of movement of the spring housing 162 and, therefore, thedrive pawl 138. The rearwardly extending portion-of the rear mount 170is secured to a bracket 174 formed as part of the housing. In theillustrative example of this embodiment of the invention, theself-contained power source may be manually operated and may comprise acompression spring 176, that provides the power for ejection of thefluent prepolymer from the device, the spring 176 is contained withinthe spring housing 162 with its rear end in engagement, with the collar172 of the end mount 170 and its forward end in engagement with a firmsurface on the rear of the driving pawl 138. When the device is at rest,the spring 176 is compressed somewhat within the housing 162 so that thehousing 162 and driving pawl 138 are in their most forward position,illustrated in solid in FIG. 13. As described below, when the device iscocked and in readiness to be fired, the housing 162 and driving pawlwill be withdrawn a distance indicated at 169, to a position shown inphantom in FIG. 13.

FIGS. 6, 9 and 10 illustrate the configuration of the triggerarrangement and its cooperation with the compression link in each ofthree positions including, respectively, a relaxed position (FIG. 6) inwhich the driving pawl 138 is in its forwardmost position, a cockedposition (FIG. 9) in which the driving pawl has been urged rearwardly tocompress the spring 176, and a released configuration (FIG. 10) in whichthe driving pawl has been released and driven forward by the spring andin which a light activation microswitch 210 has been operated toinitiate the photopolymerization process. The trigger 128 is formed toinclude a contoured surface 178 at its upper end that defines a numberof cam-like elements that engage and cooperate with the forward end ofthe compression link 158. In the illustrative embodiment, the contouredsurface 178 may be considered as having a cam edge 180, first and secondsurfaces 182, 184 that mate to define a notch 186 (FIG. 10) and a thirdsurface 186 that extends from the termination of the second surface 184.When the device is in its rest configuration (FIG. 6) the forward end ofthe compression link 158 is captured within the notch 186. A tensionspring 188 is connected between the compression link and a portion ofthe handle 102 to continually bias the compression link downwardly(counterclockwise) as seen in FIG. 6. The force of the spring 188,through the compression link 158 maintains the trigger in itsforwardmost position. A stop may be provided on the housing to limit theextent to which the trigger can pivot forwardly (clockwise).

The mechanism is operated by first squeezing the trigger to the cockedconfiguration (FIG. 9). In this configuration, the forward end of thecompression link 158 remains nested in the notch 186 but bears directlyagainst the second surface 184. in the cocked configuration, the camedge 180 of the trigger is disposed against the underside of the distalend of the compression link 158. The linkage is arranged so that as thetrigger is moved from the relaxed to the cocked positions, the pivot 160and the driving pawl 138 are urged rearwardly a desired predetermineddistance, such as the distance corresponding to the pitch between a pairof adjacent teeth 136. During the rearward cocking motion of the drivingpawl 138, the driver 130 is maintained in position by engagement of thelocking pawl 148. When cocked, the compression spring 176 is engaged andis in readiness to drive the driving pawl 138 and the driver 130forwardly, thereby advancing the plunger of the syringe.

The device is fired by further squeezing of the trigger which causes thecam edge 180 to urge the forward end of the compression link upwardlyover the second surface 184 and onto the third surface 188. The thirdsurface 188 is oriented so that when the trigger is in the firedposition, the distal end of the compression link is free to slideforwardly over the third surface. That permits the energy that had beenstored in the compression spring 176 during the cocking step to bereleased abruptly to drive the driving pawl 138 and driver 130forwardly. The forward movement is limited by engagement of the end wall166 of the spring housing 162 with the radial collar 172 on the rearmount 170.

FIGS. 16A-16C illustrate in enlarged diagrammatic detail the movement ofthe driving pawl and driver. FIG. 16A illustrates the driving pawl inengagement with several teeth, including those designated a and b of thedriver 130 with the device at rest. When the driving pawl 138 iswithdrawn rearwardly during cocking, it moves rearwardly a distanceequal to the pitch of a pair of adjacent teeth as shown, but less thantwo pitches. In this configuration, the compression spring 176 will havebeen further compressed in readiness to drive the driving pawl forward.FIG. 16C illustrates the device after it has been fired, with thedriving pawl 138 having advanced the driver 130 an incrementcorresponding to the pitch between a pair of adjacent teeth and Thedistance 169 (FIG. 13). Release of the trigger 128 by the physicianallows clockwise rotation of the trigger 128 and allows the compressionlink 158 to rotate counterclockwise until its distal end can fall fromthe third surface 188 to the first surface, resetting the mechanism inprepartion for another firing sequence. The device is then ready for thenext cocking and firing sequence.

After the device has been operated repeatedly to deplete the prepolymerliquid in the-syringe, the syringe must be replaced. That requires thatthe driver be retracted rearwardly so that it can receive the freshlyloaded syringe with a fully extended plunger. Retraction of the driver130 requires that the driving pawl 130 and locking pawl 138 bedisengaged from the teeth 136 of the driver 130. To that end, the deviceincludes a pawl release, indicated generally at 192. The pawl release192 is in the form of a generally inverted U-shaped member nested withinthe driver 130 and slidable longitudinally of the device. The pawlrelease 192 includes a top wall 191, an upwardly extending tab 193 atits rear end and a pair of laterally spaced forwardly extending releasearms 194 that fit and are movable between the arms 140 of the lockingpawl 138 and the teeth 136 on the driver sidewalls 132. The distal endof each of the arms 140, in the region of the teeth 146, is thicker thanthe more proximal portions of the arms 140 and is formed to define aninclined wedge surface 195. Identically contoured wedge surface 197 isformed adjacent the teeth 154 on the locking pawl 148. When the pawlrelease 192 is advanced forwardly, the forward ends of its arms 194engage the wedging surfaces 195, 197 to disengage them from the teeth136 on the driver 130. The driver 130 and pawl release 192 then can bewithdrawn rearwardly in unison, the arms 194 of the pawl releasemaintaining the teeth on the pawls 138, 148 out of engagement with Theteeth 136 and the driver. When the driver 130 and the pawl release 192have been retracted to the point that the ends of the arms 194 arewithdrawn from between the teeth on the pawls and the driver, the teeth136, 146 and 154 reengage. The device then is in readiness for reloadingwith a fresh syringe.

The optical system for the device includes an optical fiber assembly,indicated generally at 196 that includes an optical fiber, preferablycontained within a protective housing, such as an elongated helical coil(not shown). The optical fiber extends fully to the proximal end of theshaft 106, where the shaft passes through the rear mount 170. Thehousing 100 may be formed to include a proximal chamber that containstransition fittings 200 by which the optical fiber is transitioned fromits emergence from the proximal end of the shaft 106 to its entranceinto cable 202. The cable includes a bifurcation at its proximal end.One end of the bifurcation comprises an optical connector 204 to connectthe optical fiber to an appropriate source of activation light. Theother bifurcation includes an electrical connector 206. The electricalconnector 206 is connected to wires 208 that lead back into the housing100 into a microswitch 210 in the handle. The microswitch 210 includesan actuator 212, positioned to be actuated by the trigger 128 when thetrigger has been pulled to the fire position (FIG. 10). The electricalconnector 206 is connected to the light source such that actuation ofthe microswitch 210 will cause the light to be turned on to irradiatethe deposited prepolymer and cause it to polymerize to a non-fluentstate.

FIGS. 14 and 15 illustrate, in enlarged detail, the construction at thetip 108 of the shaft. The device may include a cylindrical tip member214 that is secured to the distal end of the tubular shaft 106. The tipmember 214 includes a plurality of lumens, including a lumen 216 toreceive the distal end of the optical fiber 218, a lumen 220 to receiveThe distal end of the liquid feed tube 120 and a pair of aspirationlumens 222 that communicate with the interior lumen 224 of the shaft106. The optical fiber lumen 216 may be provided with a reduced diameterdistal portion to receive the distal end of the fiber that has beenstripped of its cladding. An optically transparent window 226 preferablyis mounted to the distal end of tip member 214 to protect the end of thefiber. The window may, if desired, be provided with beam shapingcharacteristics. The distal end of the liquid feed lumen 220 defines anozzle 228 that includes a swirl element 230 and tip shape to effect thedesired spray pattern.

It is desirable that means be provided to prevent prepolymer liquid fromdripping from the distal tip 108 of the device. To that end, the lumen224 of the shaft 106 is connected to a source of suction to causeaspiration through the distal outlets of the aspiration lumens 222. Theaspiration lumens maybe disposed on opposite sides of the liquidemission orifice and will tend to aspirate immediately any liquid thatmight tend to drip from the outlet orifice 232. The lumen of the shaftmay be connected to a source of suction by a tube, illustrateddiagrammatically at 223 that is in communication with the shaft lumenand extends out of the housing through aperture 118. The proximal end ofthe tube may be provided with a-suitable fitting for connection to asource of suction. The suction may be applied at all times duringoperation of the device.

In order to facilitate orientation and spacing of the distal tip 108 ofthe device from the tissue to be treated, the device may be providedwith a gauging means by which the orientation and spacing of the distaltip with respect to the target tissue may be visually-assessed by thephysician. As shown in FIGS. 8, 14 and 15, the device may include a pairof feeler elements 234 attached to and extending distally from thedistal end of the tip member 214. The feeler elements 234 diverge andpreferably are provided with enlarged bumper pads 236 at their distalends. The feeler elements 234 extend a distance from the outlet orifice232 corresponding to the optimal distance of the device from the surfaceto be sprayed and irradiated. The feeler elements 234 are flexible. Theymay be formed, for example, from polyethylene. The bumper pads 236 serveto protect the tissue by providing a relatively broad area of contactwith the tissue. When the device is in place in the operative region,the physician will be observing the distal end of the device, forexample, through a laparoscope. The physician will be able to observewhen the bumper pads 236 have engaged the tissue by observing flexing ofthe feeler elements 234 which will begin to spread apart. Such spreadingcan be observed and provides an indication that contact has been made.By observing the manner and location of the pads 236 engage the tissue,the physician can verify the orientation and spacing of the tip 108 withrespect to the tissue. The gauge also may be made with a single feelerelement mounted to the shaft 106 so that it extends at an angle to theaxis of the shaft. In this embodiment, the physician can observe therelative movement of the single feeler element with respect to thedistal tip of the shaft.

The angle defined between the feelers 234 should be selected to assuresufficient separation so as not to interfere with the spray pattern ofliquid prepolymer emitted from the nozzle. The feelers 234 should bespread to be wider than the cone angle 238 defined by the spray 240.

In order to insert the device with the feelers 234 through the trocarcannula 81 (see FIG. 5) leading to the surgical site, the feelers mustbe drawn together to fit through the trocar cannula. To that end, thedevice may be provided with a sheath 242, slidable along the shaft 106and adapted to project distally beyond the tip 108 to enclose and drawtogether the feelers 234. The slidable sheath 242 can be insertedthrough the trocar cannula and is provided with an enlarged proximalcollar 244 that is too large to be inserted into the trocar cannula 81.The sheath may be shorter than the trocar cannula. When the device isinserted through the trocar cannula, the sheath will maintain thefeelers together until the proximal collar engages the proximal end ofthe trocar cannula. Further advancement of the device will cause thefeelers to emerge from the distal end of the sheath and trocar cannulawhere they will spread under the influence of their own resilience.

Although, for convenience in the foregoing description, certain featuresof the invention may have been disclosed only in connection with one ofthe embodiments, it is intended that the characteristics and features ofeach embodiment may be incorporated in the other, to the extent thatthey are compatible. For example, feeler gauges or aspiration lumens maybe provided with the embodiment illustrated in FIGS. 1-5.

It should be understood that although the invention has been describedas being used with a device having a rigid shaft, the invention also maybe employed with application systems in which the shaft, or part of theshaft, is flexible or articulated, as in a flexible or articulatedcatheter. Additionally, it should be appreciated that the invention maybe practiced with other compositions than those described explicitly inthe above-identified Hubbell patent applications including, but notlimited to, compositions that may be later developed.

It also should be understood that the foregoing description of theinvention is intended merely to be illustrative thereof and that otherembodiments, modifications and equivalents may be apparent to thoseskilled in the art without departing from its spirit.

Having thus described the invention, what we desire to claim and secureby Letters Patent is:
 1. A method of applying polymeric, non-fluentmaterial to mammalian tissue, comprising:applying an initially entirelyfluent, pre-polymeric material to the tissue by emitting thepre-polymeric material from an emission element located on anapplicator; and applying to the material actinic light from an emitterof actinic light located on the applicator for a period of timesufficient to convert the material to a polymeric, non-fluent condition.2. A method as in claim 1, the applying step comprising applying apredetermined volume of fluent, pre-polymeric material to the tissue. 3.A method as in claim 1, wherein the step of applying fluentpre-polymeric material to the tissue involves forming a coating offluent pre-polymeric material on the tissue, and the step of applyingactinic light involves converting the coating of fluent pre-polymericmaterial to a coating of polymeric, non-fluent material on the tissue.4. A method as in claim 1, wherein the step of applying pre-polymericmaterial to the tissue involves emitting the pre-polymeric material froman emission element located at a distal portion of an applicator havinga proximal portion and a distal portion, andthe step of applying actiniclight involves applying the actinic light from an emitter of actiniclight located at the distal portion of the applicator.
 5. A method as inclaim 4 wherein the step of applying actinic light further involvesactivating a source of actinic light that is connected, via an opticalconnector, to the emitter of actinic light.
 6. A method as in claim 4wherein the step of applying pre-polymeric material further involvesdispersing the pre-polymeric material from a nozzle that is a componentof the emission element, in a predetermined pattern.
 7. A method as inclaim 4, wherein the actinic light is emitted from the distal portion ofthe applicator in the same direction in which the pre-polymeric materialis applied from the distal portion of the applicator.
 8. A method as inclaim 4, wherein the step of applying actinic light involves applyingactinic light to a tissue surface in a pattern at least as large as adispersion pattern in which the pre-polymeric material is applied to thetissue surface.
 9. A method as in claim 4, wherein, following the stepof applying pre-polymeric material to the tissue surface in a firstpattern, the method involves applying actinic light to the tissuesurface in a pattern that is substantially the same shape as that of thefirst pattern.
 10. A method as in claim 4, further comprising allowing acontroller that automatically operates the emitter of actinic light toactivate the actinic light following the step of applying thepre-polymeric material to the tissue.
 11. A method as in claim 1,further comprising inserting the applicator, percutaneously, into thebody of a mammal.
 12. A method as in claim 1, further comprisinginserting the applicator via an incision into a mammal.
 13. A method asin claim 1, further comprising inserting the applicator via a naturalorifice into a mammal.
 14. A method as in claim 4 wherein the distalportion of the applicator is adapted for insertion into a patient andproximal portion remains outside of the patient, the method furthercomprising inserting the distal portion of the applicator,percutaneously, into the body of a mammal.
 15. A method as in claim 4,wherein the distal portion of the applicator is adapted for insertioninto a patient and proximal portion remains outside of the patient, themethod further comprising inserting the applicator via an incision intoa mammal.
 16. A method as in claim 14, wherein the distal portion of theapplicator is adapted for insertion into a patient and proximal portionremains outside of the patient, the method further comprising insertingthe applicator via a natural orifice into a mammal.
 17. A method as inclaim 2, wherein the step of applying a predetermined volume of fluent,pre-polymeric material to the tissue defines a first cycle of a cyclicalprocedure, the method further comprising applying a second predeterminedvolume of fluent pre-polymeric material to the tissue in a second cycle.18. A method as in claim 17, wherein the first and second predeterminedvolumes of fluent pre-polymeric material are essentially the same.
 19. Amethod as in claim 17, wherein the step of applying actinic light to thematerial is effected between the first and second cycles.
 20. A methodas in claim 1, wherein the step of applying the fluent pre-polymericmaterial involves spraying the fluent pre-polymeric material onto thetissue.
 21. A method of aiming a fluent delivery device and forirradiating fluent material delivered by the device,comprising:providing a delivery and activating device having anapplicator constructed and arranged to deliver fluent material in apredetermined pattern, the device having an emitter that emitselectromagnetic radiation in a substantially corresponding pattern;preliminary irradiating a tissue surface with light in the predeterminedpattern using the light pattern as a guide to orient the device at aselected location with respect to the tissue; thereafter delivering thefluent material onto the tissue at the location in the predeterminedpattern; and thereafter emitting electromagnetic radiation from theemitter onto the fluent material to activate the material to convert itto a non-fluent state.
 22. A method as in claim 21, wherein the step ofdelivering the fluent material onto the tissue involves spraying thefluent material onto the tissue.
 23. A method as in claim 22, whereinthe step of spraying the fluent material onto the tissue involvesdelivering a bolus of pre-polymer fluid into a gas stream moving at avelocity sufficient to atomize the pre-polymer fluid to form a spray.24. A method as in claim 22, wherein the spraying step involves sprayingthe fluent material onto the tissue in a generally conical spraypattern.
 25. A method as in claim 21, wherein the step of emittingelectromagnetic radiation onto the fluent material to activate thematerial involves emitting actinic light from the emitter onto thefluent material.
 26. A method as in claim 21, wherein the step ofdelivering fluent material onto the tissue involves delivering apredetermined volume of the fluent material onto the tissue.
 27. Amethod as in claim 21, wherein the steps of delivering the fluentmaterial onto the tissue and thereafter emitting electromagneticradiation onto the fluent material to convert it to a non-fluent statedefines a first cycle of operation, the method further comprising asecond cycle involving delivering fluent material onto the tissue andemitting electromagnetic radiation from the emitter onto the fluentmaterial to convert it to a non-fluent state.
 28. A method as in claim27, wherein each of the first and second cycles involves delivering apredetermined volume of fluent material onto the tissue.
 29. A method asin claim 28 wherein the predetermined volume of fluent materialdelivered in each of the first and second cycles is essentially thesame.
 30. A method as in claim 21, further comprising orienting thedelivery and activating device with respect to the tissue with a gauge.31. A method as in claim 21, further comprising allowing amicroprocessor to activate the emitter automatically following thedelivery of the fluent material onto the tissue.
 32. A method ofapplying, to mammalian tissue, a polymeric, non-fluent material,comprising:applying an initially entirely fluent, pre-polymeric materialto the tissue by emitting the pre-polymeric material from an emissionelement located on an applicator; and applying to the material actiniclight from an emitter of actinic light located on the applicator for aperiod of time sufficient to convert the material to a polymeric,non-fluent condition.
 33. A method of applying a polymeric, non-fluentmaterial to a surface of tissue internally of a mammal,comprising:applying percutaneously an initially entirely fluent,pre-polymeric material to a tissue surface internally of a mammal, thematerial being activatable to a non-fluent, polymeric condition byexposure to actinic light; and thereafter applying to the materialactinic light for a sufficient length of time to effect in situconversion of the material from a pre-polymeric, fluent to a polymeric,non-fluent condition.